1. Field of the Invention
This invention deals with the method of making openings of considerable size on comparatively thick reinforced concrete walls (e.g. reinforced concrete barrage).
2. Description of the Prior Art
As the opening method for reinforced concrete walls, the drilling method using a blade type concrete cutter and core driller has been known.
Owing to the limitations of cutting and drilling ability originating from the structures and facilities of cutters and drillers used in the prior opening methods, it has been almost impossible to drill openings of required size in the exact required position for reinforced concrete walls (with thickness of 5 m, 10 m, 20 m or more), unless the thickness of the wall was comparatively small, say 1 m. Even if possible, a huge number of processes and money were needed, so in reality these methods could not be adopted. For example, it was impossible to drill holes of 1 or 2 m square on an existing reinforced concrete barrage with 10 to 20 m thickness so as to penetrate a steel pipe with large diameter.
As for using explosives or hydraulic breakers, the portions which is not intended to be broken also suffer from the breaking influence, so it was impossible to adopt these methods when making an exact opening in a reinforced concrete wall.
The aim of this invention is to offer a method for making the openings of required size in the required position of a comparatively thick reinforced concrete wall (e.g. reinforced concrete barrage).